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Access to older HRSN data

Availability and access to older HRSN data depend on the time period of interest.

1987-1998

The HRSN historical background describes the goals and design of the network and outlines the characteristics of the earthquake data set for the 1987-1998 time period. We strongly suggest that you read this document before using any of the HRSN earthquake data.

Location catalog

A catalog of earthquake locations derived from the HRSN data is available:

Each catalog line contains:

  • Date and time (which may be incorrect -- see the HRSN historical background for details).
  • Hypocenter (location and depth in km)
  • Number of observations used to compute the hypocenter
  • RMS of location (in sec)
  • ID number

The NCEDC has added the following fields to the catalog:

  • Normalized File Date
    The normalized time of the date used in the filename of the waveform file. Some the times used in the waveform filenames are not normalized, eg hour >= 24, minute >= 60, etc. NO MATCH mean that no apparent waveform file could be matched to the earthquake based on the apparent time of the earthquake and the time in the filenames of the available waveform files.
  • Waveform Filename
    The best estimate as to which waveform file contains the waveform for the the event. NO MATCH mean that no apparent waveform file could be matched to the earthquake based on the time of the earthquake and the time in the waveform filenames.

Waveform Archive

The waveform file archive is available as an assembled data set These older waveforms span January 1987 through June 1998.

The waveform files are stored in UC Berkeley/LBL SEGY format. UC Berkeley/LBL SEGY files contain both the printable and binary SEGY reel headers and one or more SEGY data traces. Each data trace consists of a SEGY trace header followed by trace data in binary 16 bit integer format in big-endian byte order.

Several programs are available to read the HRSN SEGY data files:

  • bp2ms - will convert a HRSN data file to individual MiniSEED files, one per channel. The HRSN SEGY channels to SEED station and channel mapping is provided automatically by the script
  • segy2ms - is a program used by the script bp2ms to perform the data conversion from UCB/LBL SEGY format MiniSEED format.

Once the files have been converted to MiniSEED, additional programs may be used to provide the data in SAC format

  • ms2sac - converts a MiniSEED file to SAC format. The coordinates for the stations will NOT be entered into the SAC header.

Pick Files

Many of the SEGY files also have pick files (files with a suffix of .pf.) The pick files for an event are located in the same directory as the waveform file for that event. The format of the pick files will be documented in the near future.